Combination cutting drill and reaming bit



Feb. 28, 1933.,. H. D. SANDSTONE 1,899,727

COMBINATION CUTTING DRILL AND REAMING BIT Filed Aug. 8, 1930 I m'enlor Patented Feb. 28, 1933 UNITED STATES PATENT OFFICE HARVEY DAVID SANDSTONE, OF LOS ANGELES, CALIFORNIA COMBINATION CUTTING DRILL AND REAMING IBI'I.

Application filed August 8, 1930. Serial No. 473,855.

sure at the point of the bit, and for regulating the power-load to maintain a constant even motor speed.

A further object in connection with the former, is the provision of a simply constructed, readily assembled and automatically operated under-reamer wherein bolts and nuts, keys, shafting, sleeves, gearing, cog wheels, and similar structural parts are entirely eliminated.

A still further object of my invention is the provision of an effective means in the drilling of well holes for simultaneously forcing the heavier grindings released into the wall formation and thus creating a substantially 9 solid well wall.

Other objects and substantial advantages of my invention will readily appear as this description progresses.

I attain these objects by the device illustrated in the accompanying drawing, in

which:

Figure 1 is a side elevation of my device showing the reamers in expanded position.

Figure 2 is a longitudinal central section of the device indicating its structural detail, one reamer being pocketed in the bit body, another expanded as indicated in dotted lines, the cutting members shown in Fig. 1 being in outline.

Figure 3 is a plan view of the bit end showing the conical formed cutters on the line 3-3, Fig. 1.

Figure 4 is a cross-sectional view on line 44, Fig. 2, showing the relative position of the reamers pocketed within the bit body.

Similar numerals refer to like parts throughout the several views, the numeral 1 thus indicating the bit body comprising upper and lower sections 2 and 3 respectively,

interconnected by means of engaging thread member 4, section 2 at its uppermost exterior having a tapered aperture 5 threaded as at 6 for engagement with a hollow drive shaft, not shown, the opposite or lower portion of said section being channeled to provide a ball race 7 permitting said sections 2 and 3 to be freely turned in the process of connecting as is readily apparent in Fig. 2.

Incorporated in the upper portion of section 3, ball sockets 8 accommodate ball finished ends 9 of reamers 10 of which the device has three. Positioned in the bit body are pockets 11 which house the reamer cutting heads 12 of said reamers 10. The lower portion of said section 3 incorporates a plurality of cutting members 13 projecting from the conical, lower end of the bit, which are designed and construc ed on the rinciple of the threads of a wood screw, eac 1 thread to all intents and purposes having the cutting characteristics of separate cutting members, a fish tail cutting lead 14 at the apex of the bit and a plurality of outlet openings 15 immediately adjacent thereto and from which water introduced into ducts 16 passing through the bit body is expelled. Ducts 16 have branches 17 connecting with the ball race 7 the Water supply entering the ducts 16 through the hollow shaft and aperture 5, from the source of supply above, the liquid serving as amedium for flushing or washing away obstructions and dirt accumulations within the ball sockets so that the ball finished ends 9 of the reamers 10 may be free to move with minimum friction and subsequent wear.

Immediately above the cutting members 13, spiral formed lifting members 19 function to force the drilled material upwardly and away from the cutters, thus at all times having a tendency to keep the hole adjacent the cutters practically clear of the already drilled earth matter.

Ducts 16 converge as at 18, the single duct thus formed housing a spiral sleeve 20 suitably mounted, said spiral sleeve functioning to impel the water at the point of the bit, and thus considerably increase the effectiveness of the former as a cutting medium, it being a known fact that the presence of water greatly facilitates the cutting and breaking operation by simultaneously softening the earth strata and keeping the cutterscool.

Collar plates 21 of proper material suitably housed in the ball sockets 8 comprise a compensating medium for wear and the incident play resulting on the ball end 9 by its constant movement within the socket 8, the reamer cutting heads thus at all timesbeing uniform in their operating action and in enlarging the hole which the cutters 13 have drilled to a uniform diameter.

In its practical adaptation, the bit is attached to the driving shaft and operated in the usual manner. The reamers expand by centrifugal action as the speed of the drill is increased, operating on the principle of a governor. Normally housed in the pockets action of the centrifugal force.

11, the reamers offer no resistance to the revolving bit, hence in starting to drill no extra load is placed on the motor. As the latter gains momentum, the reamers gradually move outwardly and upwardly through the They are connected and balanced to the bit body so that their expansion is checked until the motor or motors have developed seventy-five per cent (75%) of their normal speed.

From the foregoing it will be evident that the power input is divided between the cutters integral with the bit body and the rotating cutter-heads disposed on the periphery, in such proportions as are governed by the speed at which the whole assembly is driven. Thus, at high rates of speed the power consumption of the cutter-heads will be in that measure greater, and the resultant diameter of the hole bored will be greater.

Now, it will be apparent that in certaln formations where the bit pursues a more or less tortuous course, a greater hole diameter is desirable and necessary to accommodate the bit and attached equipment of fixed cylindrical form. The operation of the bit of my invention is in this wise distinguishable: Instead of attempting to drill a hole of precisely uniform diameter and precisely plumb, it is sought with the bit of my invention to provide means to accommodate the bit to the form of hole inevitably resulting from conditions of unequal resistance to penetration inherent in natural formations which deflect the cutters from exact truth of progress in a plumb line.

In consequence, it is to be observed that higher rotative speeds are employed in formations which tend to deflect the bit.

The cutters cut and break loose the earth strata encountered which is simultaneously forced upwardly by the spirally formed liftfurther ground and broken up by the expanded reamer cutting heads 12, i the expanded reamers thus not only increasing the diameter of the hole drilled by the cutters 13, but also pulverizing and impressing the material they contact with against the hole wall,

theresult being a compact and solid wall,

practically all surplus loose material being forced upwardly and out of the drilled hole by the action of the lifting members 19.

As shown, the reamer cutting heads 12 are finished with sharp edges. These are hardened, machined, and finished for rough, hard, and diflicult duty, to stand practically unlimited abuse.

As many apparently widely different embodiments and changes in construction of this invention could readily be made without departing from the scope thereof as herein shown and described, it is intended that'the description and drawing shall be interpreted as illustrative and not as limiting.

Having thus described my invention, what I claim as new, novel and useful as an article of manufacture, is

1. In a well drilling device, the combinationin a bit adapted for engagement with a revolving shaft of a sectional body having juxtapositioned on its periphery spiral lifting means whereby loosened earth and drill grindings coming in contact therewith are automatically carried upwards and in contact with auxiliary reamer and cutter heads operatably positioned outwards and upwards by centrifugal force, said auxiliary reamer and cutter heads uniformly enlarging the well hole simultaneously with the operation of the drilling cutters at and adjacent the apex of the said sectional body and pounding and breaking said loosened earth and drill grindings and packing the well wall to a substantial solid surface.

2. In a well drilling device characterized by a rotary bit of sectional body, auxiliary cutter heads operated in expansion by centrifu al force and spiral lifting means dispose about the periphery of said sectional body to convey grindings upwardly, a plurality of water conveying duct means juxtapositioned therethrough and connected to the source of water-supply, said water conveying duct means converging near the bottom of said sectional body into a single duct, a plurality of outlet openings adjacent the apex of said sectional body and communicating with said single duct, a spiral sleeve mounted in said single duct, said sleeve comprising a water impelling means whereby the water prior to release from said single duct is urged forward with increased force and effect.

HARVEY DAVID SANDSTONE. 

